AMD appears to have a gaping hole in its product stack, between the ~$110 Radeon HD 7770 and ~$170 Radeon HD 7850 1GB, which needs filling. NVIDIA's ~$150 GeForce GTX 650 Ti appears to be getting cozy in that gap. AMD plans to address this $110~$170 gap not by lowering price of the HD 7850 1GB, but by introducing an entirely new SKU. Since production cost on the 2.8 billion-transistor "Pitcairn" silicon is high, and since the HD 7770 maxes out feature-set of the "Cape Verde" silicon, AMD is left with only one option, to create an entirely new ASIC, which has been codenamed "Bonaire."

According to a Hardware.info report, the first SKU based on this silicon will be named Radeon HD 7790. The chip is said to pack 896 stream processors based on the Graphics CoreNext micro-architecture. It will be equipped to perform roughly 10 percent slower than the Radeon HD 7850, which should make it highly competitive with the GeForce GTX 650 Ti, giving AMD room for further price-tweaking. Bonaire could contribute to low production cost probably by a leaner transistor count, a narrower memory bus than Pitcairn (resulting in lower number of memory chips on the card), and allowing for a more cost-effective VRM. The HD 7790 is expected to be launched in April.

Im a little behind on the info for this card, is it still supposed to be GCN 2.0, Or were hose rumors debunked?

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AMD did mention in its press conference that multiple micro-architectures could fill up one product stack (HD 7000 series). So I won't be surprised if this is GCN 2.0. If HD 7790 (896 SP, 128?-bit GDDR5) is only 10% slower than HD 7850 (1024 SPs, 256-bit GDDR5), then maybe this chip does have performance per clock boost, which could indicate GCN 2.0.

AMD did mention in its press conference that multiple micro-architectures could fill up one product stack (HD 7000 series). So I won't be surprised if this is GCN 2.0. If HD 7790 (896 SP, 128?-bit GDDR5) is only 10% slower than HD 7850 (1024 SPs, 256-bit GDDR5), then maybe this chip does have performance per clock boost, which could indicate GCN 2.0.

If there is a 896sp sku nothing else makes sense unless they plan on using 7gbps, which while not impossible would seem unlikely for a budget card. 192-bit/5ghz-rated (or something like 4600-4800 stock clock) ram seems more likely.

Since 896sp *should* take up ~150mm2 (not counting a bigger or faster bus), it makes the choice realistic. Also, the difference in voltage between current ~5ghz (1.35v) and greater (1.5-1.6v) is another thing worth considering. 192-bit just all-around makes more sense on every conceivable level.

It's competition would also be 650ti, granted not at stock like 7790. In theory 896sp would perform VERY similar clock per clock. nVIDIA may be slightly better because of more TMUs, but that's a few percent at most. In the same power envelope AMD could work some voodoo. 650ti is shoe-horned into a stunted TDP for the sake of 660 and hence overclocks into the ~1150mhz range. It's possible, if not likely, AMD could clock/powertune rate said part at stock to take on the maximum potential of 650ti (clock difference made up by bandwidth of larger bus or faster ram), and be a similar percent faster over-all than 650ti will be to a 768sp AMD part when both are overclocked (even if both perform similar at stock, which they likely will.)

IOW:

650ti = 7790 < overclocked 650ti = '8770' > overclocked 8770.

It's a pretty sound hypothetical, I think, each separated by around 10-15%. That way AMD can launch at ~130-150 and straight up take on 650ti at similar price points without worrying about losing on performance or price. Ofc, it appears more and more likely the 'xx50' parts will launch first, like '7790', likely to prop up the ASP of existing 7000 series parts as well as use the neutered part to their full clock potential (rather than artificially limit them as xx50 parts through lower stock clocks and voltage for product segmentation.)

GTX 650Ti uses 128-bit, so I don't think this SKU could step up memory bus width. Maybe it can achieve 96 GB/s using 6.00 GHz.

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Oh, totally agree. 7790 seems most likely 768sp 1075/6ghz 128-bit.

I thought we were talking the gpu, not the sku.

As I kind of glossed over above, it would not surprise me if the 7000 series includes high-clocked salvage parts of the 'next-gen' full gpus for strategic purposes (inventory-clearing?) if not something else (cost/yields of new chips, availability of a new ram spec?) and the full gpus themselves come later to replace the next gpu up. EX: 7790 fits in the stack, '8770' does not. 7790 could launch soon to compete with 650ti, 8770 later to replace 7850 when the ASP has declined to a level where a gpu of said spec should slot in given it's die size etc.

Margins are often wafer-thin in the sub-$200 market. The incentive behind 128-bit is the need for just four memory chips, a smaller ASIC package (lower pin count), and a few dozen million fewer transistors for the IMCs. To me, 96 GB/s (6 GHz @ 128-bit), or maybe a "feel-better" 100 GB/s using slightly higher clock speeds, should do for a chip like Bonaire.

I think transistor count is factored in more than die-size, in determining manufacturing cost at the foundry-level. No doubt "cost per transistor" goes down with each new (smaller) process, but it's not linear.

AMD appears to have a gaping hole in its product stack, between the ~$110 Radeon HD 7770 and ~$170 Radeon HD 7850 1GB, which needs filling. NVIDIA's ~$150 GeForce GTX 650 Ti appears to be getting cozy in that gap. AMD plans to address this $110~$170 gap not by lowering price of the HD 7850 1GB, but by introducing an entirely new SKU. Since production cost on the 2.8 billion-transistor "Pitcairn" silicon is high, and since the HD 7770 maxes out feature-set of the "Cape Verde" silicon, AMD is left with only one option, to create an entirely new ASIC, which has been codenamed "Bonaire."

AMD did mention in its press conference that multiple micro-architectures could fill up one product stack (HD 7000 series). So I won't be surprised if this is GCN 2.0. If HD 7790 (896 SP, 128?-bit GDDR5) is only 10% slower than HD 7850 (1024 SPs, 256-bit GDDR5), then maybe this chip does have performance per clock boost, which could indicate GCN 2.0.

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Dont these contradict each other given reports that if it is GNC 2.0 or a re-spin of GNC 1.0. AMD early reports were that it had tape-out in June 2012 at Samsung plant in Texas.

GTX 650Ti uses 128-bit, so I don't think this SKU could step up memory bus width. Maybe it can achieve 96 GB/s using 6.00 GHz.

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I definitely agree with btarunr, 128-Bit would stay cost effective, while don't think they'll need much over 90Gb/s in bandwidth to achieve what the need to play at 1920x while remain under the 7850. And has AMD/ATI ever had a 192-Bit card? I can't recall any... honestly.

if it really is GCN2, it could be the new 4770 minus the "manufacturing process" change (55nm to 40nm)

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I understood what you meant... it’s what’s called a "pipe cleaner". Very may well be GCN2 initial analysis to see how maneuvering and placement (a juggling of what on the silicone sections) to improve their interaction and efficiency to improve TDP.

Edit... Lastly I see this helping "reign-in" the selling the "Pitcairn" at as low as $150. I think AMD Pitcairn production at this point has the XT in abundance. They'd rather curtail the 7850's almost completely, and give the prominence of sales to 7870’s at around $200. That places the GTX660 and even the GTX600Ti back on it's heels in a price position similar to what the GTX650Ti was having against the 7770/7850, while consider AMD has the 7870 Tahiti(LE) at $240.